I've just been asked to board and skim a loft conversion. it has kingspan 50mm in between rafters, is this enough insulation with 12.5mm plasterboard? or do i need foil/polystyrene backed boards, should i be using fireline boards. now chaps i could do with knowing the regs on this and not just an idea of what maybe best to do. dj.
We have 80mm Celotex sheets, as recommended by our local Building Control Office. Give them a call for advice. It's a minefield to work out the calcs yourself. It comes under section L1 of the regs. Click Here Hope it helps.
Talk to your local building control - I've just had to put in 90mm Celotex between rafters with 12.5mm foil backed plasterboard and skim.
a bit of feedback for you people out there. 50mm kingspan in between rafters then 50mm insulation backed plasterboards recomended by local regs. hence:-100mm insulation for the job. once again...thanx. dj.